Process of and apparatus for grading solid materials



Apr. 24, 1923. 1,452,815

c. J. REED PROCESS OF AND APPARATUS FOR GRADING SOLID MATERIALS 1 FiledApril 25, 1919 2 Sheets-Sheet 1 Apr. 24, 1923. 1,452,815

C. J. REED PROCESS OF AND APPARATUS FOR GRADING SOLID MATERIALS FiledApril 25, 1919 2 Sheets-Sheet 2 llll l u. l

Patented Apr. 24, 1923.

CHARLIES J. REED, OF GLENSIDE, PENNSYLVANIA.

PROCESS OF AND APPARATUS FOR-GRADING SOLID MATERIALS.

Application filed April 25, 1919. Serial No. 292,718.

To all whom it may concern:

Be it known that I, CHARLESIJLIREED', a citizen of the United States,residing at .Glenside, county of Montgomery. and State of Pennsylvanla,(whose post-office address.

is 507 Brannan Street, San Francisco, California), have invented certainnew and useful Improvements in Processes of and Apparatus for GradingSolid Materials, of which the following is a specification.

In Letters Patent of the United States No. 1,291,137 I have described amethod of and apparatus for causing a mass of solid particles, under theinfluence of an upwardly flowing medium of uniform distribution, toacquire a condition of liquid mobility in which there is an automaticstratifica tion of the solid particles into horizontal layers and aseparation of those having similar properties as to size and densities,these layers maintaining a certain relative position depending on theirproperties and at the same time maintaining their liquid mobilit In theLetters Patent above referred to I have described and claimed a methodof and means for removing separately these stratified products b causingthem to flow out of the apparatus 1n an initially upward direction inorder not to produce horizontal currents in the flowing medium. whichhorizontal currents, and all irregular currents. tend to interfere withand destroy the stratification and separation of the solid particles.

The method described by me in the above named Letters Patent ofproducing permanent liquid mobility and permanent stratification of thesolid particles by means of an upwardly flowing medium of uniformdistribution is highly eflicient and practically instantaneous inoperation. But a practical final separation of the particles of theseveral strata requires a means of removing these strata from theapparatus without interfering with this Stratification. Owing to theextreme mobility of this mass any influence tending in any way tointerrupt or disturb either the uniformity of distribution or the upwarddirection of the flowing medium instantly destroys or impairs thestratification. In the Letters Patent referred to I have shown a meansof accomplishing this with good results by causing solid particles to becarried out along with the stream of upwardly flowing medium and to bedrawn initially upward through tubes or pipes acting -a s slphons orthrough suction. While this arrangement accomplishes the purpose 1n aneflicient manner, it is subject to limitatlon owing to the fact that themotion of the mass, that is of the solid particles and the movingmedium, towards the exit tubes causes some disturbance of the flowingmedium or irregularity in the current and, conscquently. destrovs tosome extent the stratification, even though the tubes may be numerousand uniformly distributed. This seems to be an inherent defect in anymethod.

of removing the solid particles which requires also the simultaneousremoval of part of the flowing medium.

In the method and apparatus herein described I accomplishde thecontinuous removal of the solid particles after Stratification through asuitable outlet without the removal of any part of the flowing mediumand without in any Way disturbin the same.

I accomplish this object by t e method and the mechanism illustrated inthe accompanying drawing, in which Fig. 1 is a vertical section of oneform of the apparatus taken on line AA of Fig. 2. Fig. 2 is a verticalsection of the same on line BB of Fig. 1. Fig. 3 is a top view of thesame. Fig. 4 is a vertical section of the modified form of the apparatustaken on line CC of Fig. 5. Fig. 5 is a vertical section on line DD ofFig. 4, and Fig. 6 is a top view of the same after removal of thehopper.

Similar numerals refer to similar parts throlwhout the several views.

Referring to Figs. 1, 2 and 3, 1 is a rectangular receptacle of suitablematerial for sustaining pressure closed on all sides except the top.which is closed by a sheet of felt 3 or other porous, uniformlyresisting material. Above this felt, resting on its periphery andholding it in place is a rectangular frame, 4, preferably of metal,which, with the felt acting as a bottom, constitutes the separating pan.2 represents an inlet tube for the injection under suitable pressure ofa flowing medium, which, for illustration, may be water- 6 represents ahopper and 9 a vertical tube for the introduction of the granularmaterial into the separating pan 4 near the bottom. 5 is an outlet spoutat the top of the pan for the exit of the flowing medium after it haspassed to a considerable height above the level of the solid material.11 and 12 are receptacles outside of the pan, but connected with itthrough openings 7 and 8 respectively in the side. walls 18 and 19respectively. These receptacles are closed on all sides except the topand may also be closed at the top. But those shown in the drawing arenot closed at the top, the walls 20 and 21 respectively extending to thelevel of the walls 18 and 19. These outside receptacles are adapted tobe'filled with the flowing medium and to retain it to the same level asthat in the pan 4 and to hold the same level, and must have no outletthrough which the flowing medium may escape. Under these conditions whenthe apparatus is filled with the flowing medium to the level at which itoverflows through 5 a constant level will be maintained in all thereceptacles 4. 11 and 12. and while there will be free communicationbetween them all through the openings 7 and 8. there will be no furtheractual flow of the medium through these openings and they may be openedor closed by sliding doors l3 and 22 or partly closed without any of theflowing medium passing through in either direction. It is through theseopenings and under these conditions that I remove thesolid particlesfrom the various strata without removing the flowing medium. 15 and 16are vertical rods attached to the doors 13 and 22 respectively andextending to a considerable height above the walls to be used inmanipulating the doors. It is evident that the rods may be arranged tooperate or be held or adjusted either by hand, as shown, or by anysuitable controlling mechanism not shown in the drawing.

In the operation of this mechanism the flowing medium, water. forexample, is forced under pressure into 1 through 2 and itpasses upwardlythrough the felt 3 by which it is uniformly distributed. \Vhen itreaches the height indicated by the line 23 it begins to flow outthrough the spout 5 and the constant level 23 is thereaftermaintained.The granular material 17 is then introduced in a steady stream through 6and 9. In the bottom of 4 this material acquires liquid mobility andflows out horizontally and forms the layers 24 and 25 which are held ina condition of mobile suspension. Vhen the layer 25 acquires a heightabove the level oi the opening 8 the door 22 is raised and the particlesin the layer 25 are allowed to flow out through the opening 8 into thereceptacle 12. When the layer 24 acquires. a height above the level ofthe opening 7 the door 13 is raised and the particles in the layer 24pass out through the opening 7 into their receptacle 11. The doors maybe thus manipulated to allow the exit of only the desired material intoits receptacle. There is evidently no limit to the number of openingsand receptacles that may be used, though for the purpose of illustrationI have shown onl two.

It is also QYlt ent that instead of the open receptacles 11 and 12 I mayuse, as heretofore stated, receptacles entirely closed and filled withthe flowing' medium. In that case the receptacle would be a blind pocketand need not be of any particular height, but in that case the doors l3and 22 must be operated by a different device, or the rods 15 and 16might be placed inside of the pan 4.

Figs. 4, 5 and 6 show respectively a vertical transverse, a verticallongitudinal and a top view of a modified form of the apparatus. In Fig.6 the hopper 6 is removed. In this form of apparatus the entiremechanism is submerged in a receptacle 33 having walls 28 and'29 filledwith the flowing medium. This receptacle is divided by partitions 26 and27 into compartments or pockets 3t), 31 and 32. These partitions extenddown into the pan nearly to the felt. The separating pan is mountedwithin the receptacle 33 and extends through the partitions 26 and 27.The walls 1 are cut down as shown, the three portions 36, 37, 38 beingof different heights in the difi'erent compartments. The openings 7 and8 and their doors are dispensed with. The inlet pipe 2 extends throughthe wall 29 of the receptacle 33.

In the operation of this modified form the apparatus is allowed to fillwith water through 2 until it overflows from the spouts 5, 5' at the topof the receptacle 33. The granular materials introduced through 6 and 9and Stratified and flows under the partition 26 and 27 until the densestlayer 25 in all three compartments rises to the level of 36, when itwill fiow over the walls into the pocket 32. lVhen the next layer 24reaches the height of 37 it will flow over into the pocket 31 and whenthe third layer reaches the height 38 it will flow over into the pocket30. From these pockets the material may be removed by any suitablemeans,not shown either continuously or by interrupting the operationwhen the pockets are filled. Evidently I am not limited to a particularnumber of partitions, pockets or products.

Whatever may be the form of apparatus or the nature of the mobilemedium, the essential and sufficient conditions are that the stratifiedparticles shall pass out from the moving portion of the medium to aportion of the same medium at rest without transferring the medium.These conditions require that the medium at rest shall be a fixed volumeconfined in a receptacle from which it cannot escape or undergo changeof volume. By being at rest I do not mean that there is absolutely nomotion at and adjacent to the opening between the two receptacles wherethe flowing portion and the ortion at rest are in contact. There willlie some irregular, eddying motion at that point, but that does notprevent the solid particles from passing through the opening into thevolume of medium at rest without transporting any of the medium withthem.

When I speak of the moving or transporting the solid particles withoutremoving the flowing medium I do not mean that a few atoms or moleculesof the medium in actual intimate contact with the solid particles maynot be removed, but I mean that no measurable and, hence, no detrimentalquantity is removed. Gil the contrary, instead of conveying the mediumwith it, when a solid particle passes out of the upwardly flowingcurrent through the opening into a receptacle of fixed volume filledwith the medium, a volume of the medium equal to the volume of the solidparticle passes in the opposite direction through the opening to makeroom for the entering solid particle. In this way every particle whichpasses out of the flowing current leaves no disturbance behind itbecause an equal volume of the medium takes its place from thereceptacle into which it passes.

I claim:

1. The process of grading solid particles, which consists in holding amixture of the solid particles in a suspension zone of a suspensionmedium in a condition of stratified suspension and withdrawing particlesfrom diiferentstrata out of the suspension zone into separate zones ofrelative quiet in the suspension medium.

2. The process of grading solid particles, which consists in subjectinga mixture of the solid particles in a suspension medium to forcescausing stratification and withdrawing particles from different stratalaterally into separate zones of relatively quiet in the suspensionmedium. I

3. The process of grading solid particles, which consists in subjectinga mixture of solid particles in a suspension medium to the buoyantaction of a fluid'medium causing stratification and withdrawingparticles from diiferent strata laterally into separate zones ofrelative quiet in the suspension medium.

4. The process of grading solid particles, which consists in subjectinga mixture of the solid particles in a suspension medium to forcesholding it in a condition of stratified suspension by the action of anupwardly flowing mobile medium/and allowing particles to pass laterallyout of different strata into separate zones of relative quiet in thesuspension medium.

5. A'separator for grading solid particles, comprising a vesselcontaining a suspen' sion medium, means for holding a mixture of thecondition of stratified suspension, means for particles 'in the mediumin a restraining lateral movement of the particles out of the suspensionzone and means for allowing particles to pass laterally out of differentstrata into separate zones of relative (knot in the suspension medium.

6. separator for grading solid particles, comprising a vessel containinga suspension medium, means operative within a limited zone in the mediumto hold a mixture of the particles in a condition of stratifiedsuspension and means for allowing particles from different strata topass laterally out of different strata into separate zones of relativequiet in the suspension medium.

7. An apparatus for grading solid particles, comprising the pan orreceptacle having peripheral walls and a porous bottom, means forintroducing the solid particles, means for introducing a medium ofsuspension into the pan through the porous bottom, a receptacleinclosing the pan and divided into compartments by partitions, a portionof the pan extending into each compartment and portions of the wall ofthe pan in different compartments extending to difierent heights, theenclosing receptacle being adapted to retain the medium of suspensionabove the walls of the pan and at the same level in two or morecompartments.

8. In a separator for grading solid particles a pan having a peripheralwall and porous bottom, means for introducing a medium of suspensioninto the pan through the porous bottom, a receptacle outside of andinclosing the pan, and having walls extending to a higher level than thewalls of the pan, said receptacle adapted to retain the medium at aheight above the wall of the pan.

9. A separator for grading solid material, comprising a container havinga transverse porous wall, a second container adjacent the said firstcontainer, a medium of suspension in said containers, means forintroducing material to be graded into the first container, meansoperative through the said porous wall for maintaining the material inthe first container in a state of mobile suspension and stratification,means permitting the material forming a stratum to float out of thefirst container into the second container, and means operative tomaintain the medium of suspension under substantially the same pressurein both containers at the level of said stratum.

10. A separator for grading solid material, comprising a containerhaving a transverse porous wall, a plurality of additional containersadjacent the said first container. a medium of suspension in saidcontainers,

means for introducing material to be graded into the first container,means operative through the said porous wall for maintaining thematerial in the first container in a state of mobile suspension andstratification,

means permitting the materialvforming different strata to float out ofthe first container, each into a different additional container, andmeans operative to maintain substantially equal pressure between themedium in each additional container and the medium in the firstcontainer at the levels of the respective strata.

11. A separator for grading solid material, comprising a containerhaving a transverse porous wall, a second container adjacent the saidfirst container, a medium of suspension in said containers, means forintroducing material to be graded into the first container,meansoperative through the said porous Wall for maintaining the materialin the first container in a state of mo bile suspension andstratification, means per- 1 mitting the material forming a stratum tofloat out of the first container into the second container, and meansfor maintaining the medium in the first and the medium in the secondcontainer at substantially equal levels.

12. A separator for grading solid material, comprising a containerhaving a transverse porous wall, a plurality of additional containersadjacent the said first container, a medium of suspension in saidcontainers, means for introducing material to be graded into, the firstcontainer, means operative through the said porous wall for maintainingthe material in the first container in a state of mobile suspension andstratification, means permitting the material forming different stratato fioat out of the first container, each into a different additionalcontainer and means for maintaining the medium in each of the additionalcontainers and the medium in the first container at substantially equallevels.

13. A separator for grading solid material, comprising a containerhaving atransverse porous Wall, a second container adja cent the saidfirst container, a medium of suspension in said containers, means forintroducing material to be graded into the first container, means forintroducing a stream of suspension medium through the porous wall tomaintain the material in the first container in a state of mobilesuspension and Stratification, means permitting the material forming astratum to float out of the first container into the second containerand means operative to maintain the medium of suspension undersubstantially the same pressure in both containers at the level oi saidstratum.

CHARLES JOHN REED.

